11191861 has 2 divisors, whose sum is σ = 11191862. Its totient is φ = 11191860.

The previous prime is 11191847. The next prime is 11191867. The reversal of 11191861 is 16819111.

11191861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8236900 + 2954961 = 2870^2 + 1719^2 .

It is a cyclic number.

It is not a de Polignac number, because 11191861 - 2²³ = 2803253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11191867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5595930 + 5595931.

It is an arithmetic number, because the mean of its divisors is an integer number (5595931).

Almost surely, 2^11191861 is an apocalyptic number.

It is an amenable number.

11191861 is a deficient number, since it is larger than the sum of its proper divisors (1).

11191861 is an equidigital number, since it uses as much as digits as its factorization.

11191861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 28.

The square root of 11191861 is about 3345.4238894346. The cubic root of 11191861 is about 223.6835787989.

The spelling of 11191861 in words is "eleven million, one hundred ninety-one thousand, eight hundred sixty-one".